Ads are coming to virtual reality (VR). Though still experimental, Google’s Advr project will let advertisers sell ads within immersive virtual environments, just like the in-app popups we avoid so feverishly today.

The latest example of Google’s intentions is buried within Area 120, the company’s cheekily named internal incubator for side projects. It’s billed as a way to “help small teams rapidly build new products in an entrepreneurial environment.” This is where Google employees spend their time when working on their “20 percent projects,” or the “fun” stuff they do with company resources (which has yielded some cool products, including Google News). The platform is comprised of several smaller projects, such as a booking service and a learn-to-code app. There’s even a personal stylist service.

Advr – which you may have guessed is probably a mashup of “ads” and “VR” – is where things get really Google-y. “Developers and users have told us they want to avoid disruptive, hard-to-implement ad experiences in VR,” writes Google. “So our first idea for a potential format presents a cube to users, with the option to engage with it and then see a video ad. By tapping on the cube or gazing at it for a few seconds, the cube opens a video player where the user can watch, and then easily close, the video.”

Google wants to make virtual ads “easy for developers to implement, native to VR, flexible enough to customize, and useful and non-intrusive for users.” It’s possibly the clearest example of Google looking at virtual reality as a platform rather than an experience. The company makes the bulk of its cash from ads, which it distributes across various platforms and delivery methods. Adding ads to VR seems like a natural fit for the company.

It’s just not clear how deep this rabbit hole will go. Google controls Daydream, the Android-focused VR platform, but it’s been slow to bring it to the mass market. (Samsung leads the way for mobile virtual reality with Gear VR, but doesn’t have a long history of playing nice with Google.)

When it comes to VR ads, Google isn’t the only pioneer in the space. Adobe is also experimenting with these kinds of advertisements, and ad-focused startups exist, as well (though you have to assume they’ll just be acquired by larger firms if VR ads become incredibly popular). We still don’t know where this will lead, but the “freemium” model is alive and kicking in VR.